A Comprehensive Review of Next-Generation Grid-Scale Energy Storage Technologies and Their Role in a Sustainable Energy Future

Grid-scale energy storing technologies are critical for maintaining grid stability and managing intermittent renewable energy sources. They play a significant role in the transition to sustainable energy for future purposes. This review looks at recent innovations in various energy storage systems (ESSs). These include advanced batteries such as solid-state, flow, lithium–sulfur, and sodium-ion. These batteries improve energy density, safety, lifespan, and cost-effectiveness. The review also explores thermal energy storage technologies such as molten salt, phase change materials, and cryogenic systems. These technologies store and manage thermal energy efficiently. Mechanical storage methods, such as pumped hydro, compressed air, and flywheel systems, provide scalable, long-duration support. Hydrogen and power-to-gas technologies, including green hydrogen and synthetic methane, also offer a promising way to store surplus renewable electricity. These technologies convert excess energy into clean fuels, helping to decarbonize industries and transportation. Emerging gravity-based storage systems and supercapacitor-hybrid technologies are also addressing storage challenges related to intermittency. They provide high-efficiency, long-duration storage. Virtual power plants (VPPs), blockchain for distributed energy exchange, and artificial intelligence-driven optimization are among the recently developed software technologies, which are simplifying ESSs. These modern technologies facilitate the addition of energy storage devices into the grid. Still, certain issues demand attention. The start-up expenses, desire for environmentally friendly products, and restrictions one must follow make it still difficult. It is still challenging because of the high start-up costs, demand for ecologically friendly items, and rules one must follow. This study underlines the importance of continually producing new ideas and of having policies supporting them. These projects will help to acquire energy storage devices for growing populations of people. They will help build a more dependable, reasonably priced, and long-lasting energy infrastructure over time.